Rubber-mixer



D. R. BOWEN AND C. F. SCHNUCK.

RUBBER MIXER.

v APPLICATION FILED JAN. I3. 1919.`

1,357,21 7. I Patented Nov. 2, 1920.

2 SHEETS-SHEET 1.

will". '11n/r D. R. BOWEN AND ,C. F. SCHNUCK.

RUBBER MIXER.

APPLICATION FILED JAN. I3, I99.

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UNITED STATES PATENT OFFICE.

DAVID R. BOWEN AND CARL F. SCHNUCK, 0F ANSONI, CONNECTICUT,

AssIGNons 'ro FARREL FOUNDRY AND MACHINE COMPANY, OANSONIA, CONNECTICUT, A COR- PORATION OF CONNECTICUT.

RUBBER-MIXER.

Patented Nov. 2, 1920.

Original application filed September 18, 1917, Serial No. 192,030. Divided and this application filed January 13, 1919.

To all whom t may concern -V Be it known that We` Dxvm R. BOWEN an CARL I". SCHNUCK, both citizens of the United States, and both residing in Ansonia, county of New Haven, State of Connecticut, have invented certain new and useful Improvements in Rubber-Mixers, of which the following is a full, clear, and exact description.

This invention relates to rubber mixers of the kind described in-our application. Serial No. 192080, of which the present application is a division.

The 'present improvements relate especially to a method of and means for charging material into the working chamber in which the mixing operation `takes place under the action of the rotaly mixing element. The material is Worked back and forth in the chamber from one end. to the other by blades on the rotor, until the mass, (which usually consists initially of rubber chunks and powdered pigment or filling material) is' reduced to the desired homogeneity and plasticity.

)ne of the primary objects of our invention is to furnish a machine of this type, and a methodof operating the same, whereby the material can be charged into the mixing chamber in avery simple and convenient V.

nother object of the invention is to provide a rubber mixer wherein material to be mixed can be readily charged by gravity into a mixing chamber in which the material is being worked back and forth, during the operation of mixing.

Another object of the invention is to furnish a rubber mixer in which the material is Worked back and forth in the chamber under heavy pressure of the rotor during mixing but in which, nevertheless, material to he mixed can be-introduced into the chamber freely during rotation of the rotor. For

'1 this purpose an opening in the end Wall of the chamber is provided which is so located that such material is conducted easily into a void or area of low pressure at the rear face of one of the rotor blades, whence it is taken up and mixed with the mass.

YTo these and other ends, the invention consists in the novel features and combina- I machine taken on line Serial N0. 270,833.

tions of parts to be hereinafter described and claimed. i

I In the accompanying drawings,

Figure 1 is a front elevation of a rubber mixer embodying our invention.

Fig. 2 is a transverse central section of the 2-2 of Fig. l.

Fig. 3 is a vertical transverse section on line 3-3of Fig. 1.

Fig. 4 is a section on line 4-4 of Fig. l, looking doWn, showing the rotor in place.

Fig. 5 is a section on line 4`4 of Fig. 1, looking up, the rotor being omitted, and

Fig. 6 is a fragmentary longitudinal section of the machine.

In its general features, the machine selected for illustration is the same as that disclosed in our application, Serial No. 192030, previously mentioned. The mixing chamber 20, of generally cylindrical shape, is mounted between suitable standards or end frames 21 having heads 22 which close the cylinder at the respective ends. A rotary mixing element or rotor 23 having a horizontal shaft 24 with bearings 25 in the cylinder heads is arranged Within the mixing cylinder. The top part of the chamber is closed, but at the' bottom, said chamber is provided with a dischargev opening 26, formed in a casting 27, which constitutes approximately the lower half of the chamber. The upper section 28 of the chamber is provided With an intermediate transverse extrusion rib 29, which cooperates With the blades of the rotor, in the manner described in our application, Serial No. 191413. The rotor is provided With blades 23EL diametrically located on the rotor shaft, one of 'said blades being located on one side of the extrusion rib, and the other being located on the other side. These blades are arranged at such an angle on the shaft as to Work the material back and forth in the mixing chamber and squeeze it through the space between the extrusion rib and intermediate part of the rotor'. The blades make substantial contact With the respective end Walls of the mixing chamber and each blade has a Working face Which forces the material toward the center of the chamber and simultaneously meshes or smears it against the side Wall of the chamber before it reaches the extrusion,

rib. ln this manner, vthe material is pressed charging opening 32 is formed in section 27 atv the 'ront'of the machine, said opening 32 being located at the lower part of a charging hopper 33. The charging opening is controlled by a suitable gate or valve 34, which is operated in the manner described in the parent application. 'l` he cylinder 30 is provided at the front of the machine beneath the charging opening 32 with a discharge opening 35 which can be closed by a swinging door 36. The door is hinged at one side of the opening 35 by a hinge 37 and at the opposite or free edge of the door, a locking device 38 is provided. rlhe piston 31 is provided with a Vdownwardly extended piston rod 39 working in a'hydraulic cylinder 40. Suitable lpressipre Huid connections 41, 42 permit the raising and lowering of the piston 31 in a manner which it will not be necessary to describe in detail.

ln addition to the main charging hopper, we provide the mixing chamber with a sup- -plementary charging opening by means oi which filling or coloring matter can be added to the batch during the mixing. lnthe example shown, we provide an inlet port 43 in one of the cylinder heads 22, at a point which is immediately adjacent an end edge of one of the blades, at some time during rotation of such blade. rlhis inlet port 43 which is eccentrically located with respect to the cylinder head ,so as to lie in the path of rotation of the blade or blades in that end of the cylinder, may advantageously be slanted or relieved onf the `lower side, as shown at 44, so as to permit the rubber to 'slide byand the pigment to slide into the chamber. The port communicates with a bore or passage 45 in the cylinder head, which leads up to a charging hopper 46 mounted on the end of the mixing chamber. ln the hopper 46 and Apassage or duct 45, an agitator of suitable kind may be provided for stirring the powder or other material which is being introduced into the mixing chamber so as lto prevent it from becoming clogged in the hopper' or in the passage leadingdoiiuiwardly therefrom. ln the form shown, agitator 47 comprises a cap piece48, 'adaptedto rest on the upper edge fofthe lhopper"and having a sheet metal' plate extending down into and fitting against the sidewall of the hopper and the passage 45. By rotating the agitator, thechamber.

Letztere material will be scraped oli" the surfaces ofv the charging device to which it adheres, "soi that it will pass freely by' gravity into the passage 45 .and thence into the mixing 7G The operation of the machine is substantially as lfollows: Supposing the parts tobe in the position shown in Fig. 2, the door 36 is closed and locked, and the rubber or other material to be treated is charged into the cylinder 30, through the hopper 33, and main charging opening 32. rlhe gate 34 is then. closed, and the pressure piston 31 is raised, so as to carry the material up in the cylinder 30, and in the lower part of casing section 27, into contact with the blades of the rotor 23, which at this time is in rotation. rthus the piston 31 carries the material into working position and, the fluid pressure on the piston being continued, the latter holds the material tightly in contact with the rotor blades, so that such blades will have a very thorough kneading or working action, the blades at opposite sidesof thev rib 29 smearing the mass against the side 90 wall of the chamber, and at'the same `timel forcing it toward the center, as previously described. l h Filling or coloring matter can be added to the batch, during the mixing, by way of the hopper 46 and its associated duct 45 and inlet port 43. ln spite of the fact that the batch of material in the chamber is subjected to relatively heavy pressure by the piston or raml 31, the spaces at the rear faces ofthe rotor blades 23a'are not completely filled with" material, and in such spaces there exist voids or areas of low pressure caused by the rotation of the blades. HWe [ind that material to be mixed, for examplegpowdered. pigment, `can be readily introduced into the mixing chamber if it is injectedl into the vacant space or spaces back of the blade or blades. The powder or other material introduced into the hopper 46 slides down by gravity throughthe duct 45 and inlet port 43 into one end of the mixing chamber. At one point in the rotation of thecorresponding blade, the inlet port 43 is wholly or partly 115 cut off by the end edge of the blade, but when the blade passes beyond the inlet port, there is a free passage for the material into the mixing chamber in the area of low pressure at4 the rear face of the blade. The ma- 120 terial at this time slides into the mixing chamber, and is added to and mixed with the batch of material already in the chamber. lVhen the'treated mass has become plastic and homogeneous, and it is desired to dis- 125 charge the machine, the pistoni-3l is lowered by `suitable manipulation ofthe fluid pressure valves'and the material drops down into the cylinder 30 with the piston. The material is stripped off -trom the rotor and 130 los falls down onto the upper surface of the niston. The'door 36 being then opened, the material can be readily taken out of the cylinder 30.'.

It will be obvious that we do not limit ourselves in all aspects of the invention to a machine in which an opening at oneend'ofy -the mixing cylinder for the charging or feeding of the material is a supplementary or auxiliary charging opening. We have discovered that a machine of the character shown may be-advantageously charged or fed from the end during the rotationjof the mixing blades owing to the existence of one or Vmore low pressure areas or voids at the chamber end behind the rotor blade or blades. Into such a low pressure area or void, material to be treated may be charged readily by gravity and such material need not necessarily be in powdered form, as various changes in the procedure herein described, as Well as in the details of the apparatus, may be made without departing from the scope of our'invention.

We do not claim herein the provision of a rubber mixer having means for charging the working chamber from beneath, as claimed in our application Serial No. 192,030, above mentioned.

Furthermore, we do not claim herein the means for or method of mixing rubber` or similar material by a mixing extrusion action, as claimed in our applications, Serial,

Nos. 191,413 and 223,537,

What we claim is: 1. In a machine of the character described, a working chamber, a rotor therein respectively.

which forces the material back and forth in said chamber, said chamber having a, charging opening in its end wal 2. In a machine of the character described, a working chamber, and a rotor in said chamber which forces the material alternately from one end of the chamber to the other, said chamber having a charging opening at one end thereof.

In a machine of the character des scribed, a working chamber, a rotor in said chamber which alternately works the material from one end of the chamber to the other, said chamber having a. charging opening in its end wall, and a hopper associated with said charging opening.

l21. In a machine of the character described, a horizontally arranged working chamber, a lrotor therein for working the material back and forth in said chamber, means for charging the main part of the material into the chamber, and a supplementary charging hopper for coloring material or the like, leading into the chamber.

5. In a machine of the character described, a horizontally arranged working chamber, a rotor therein for Working the material back'and forth in said chamber,

'means for charging the main part of the 6. In a machine of the character described,l

a working chamber, a horizontal rotor in said chamber for working the material. back and forth, said chamber having a charging opening in the end wall thereof, a charging hopper in communication with said opening, and an agitator located within the hopper.

7. In a rubber mixer, a working chamber, a bladed rotor therein for moving the material in said chamber from one end of the same toward the other and back again while maintaining it in Contact with the chamber wall and thereby mixing said material, said chamber having an end opening through which the material is moved into a void in the chamber. v

8. In a rubber mixer, a working chamber, and a horizontally disposed rotary element in said chamber having a blade with 'a front face for mashing and mixing the material, said chamber having a charging opening through which material to be treated is conducted into the space at the rear face of the blade as the latter rotates.

9. Ina rubber mixer, a working chamber, a horizontal rotary element therein having a blade for mashing the material against the side wall of the chamber and simultaneously moving it away from the end of the chamber, said chamber having an endcharging opening for material to be treated, through which the material is conducted by gravity into the space behind the blade.

10. In-a rubber mixer, a working chamber, a horizontal rotary element therein having a blade for mashing the material against the side wall of the chamber and simultaneously moving it away from the end of the chamber, said chamber having a charg ing opening for material to be treated, through which the material is conducted by gravity into the space behind the blade, said charging opening being located in the end wall of the Working chamber.

11. In a rubber mixer, a working chamber, a rotary shaft therein having inclined blades with front faces which mash the material against the side wall of the chamber treated is charged by gravity into a void at the rear face of one of said blades.

13. In a rubber mixer, a working chamber, a bladed rotor therein for working the material backfand forth in said chamber,

. said chamber having an opening in one of its ,end walls through which material may be charged by gravity during the mixing operation.

14. In a rubber mixer, a working chamber, a`bladed rotor therein for working the material back and forth in said chamber, said chamber having an opening in one of its end walls through which material is charged by gravity during the mixing operation int-o a void at the rearface of one of the rotor blades.

15. In a rubber mixer, a working chan ber, a rotor therein, having blades in substantial contact with the respective end wallsl of the chamber and` arranged to move the material back and forth in said chamber, said chamber having an opening in one of said ends walls for the ingress of material to be treated..

16. In a rubber mixer, a working cham-I ber,.a rotor therein, having blades in substantial Contact with the respective end walls of the chamber and arranged to move the material back and forth in said chamber, Said chamber having an opening in one of said end walls for the ingress of material to be treated, said opening being located in the path of one of the rot-or blades and alternately covered and uncovered by such blade.

17. In a rubber mixer, a working cham'- ber, having an end wall, a rotor in said chamber having a blade rotating in substantial contact with said end wall and adapted to move the material away from said wall toward the center of the chamber, said chamber having a feed opening in said end wall alternatelyclosed and opened by said blade as the latter rotates.

18. In a rubber mixer, a working chamber having a curved side wall and a substantially fiat end wall, a rotor insaid cham-Y ber having a blade adapted to rotate in substantial contact in said end wall and to move 'material away from said end wall toward the Arotating in substantial contact with the respective end walls for moving the material Lemma back and forth in said chamber, said chamber having an inlet opening alternately closed and opened by one of said blades' in the rotation thereof. i y

20. In a rubber mixer, a working chamber, a bladed rotor in said chamber for moving the material back and forth, said chamber having a feed opening alternately opened and closed byl one of said blades in therotation thereof.

21. In a rubber mixer, a Working chamber, a bladed rotor in said chamber for mov ing the material back and forth, said chamber having a feed opening alternately opened and closed byone of said blades in therotation thereof, said feed opening being adapted to communicate with a vacant-'space at the rear'faceof the blade. v

22. The method of mixing rubber, which comprises working the material back and forthin a suitable mixing chamber by means of suitable rotary mixing blades, and introducing additional material into the chamber.

from the end of such chamber.

23. The method of mixing rubber, which comprises working the material back and forth in a suitable mixing chamber bymeans of suitable rotary mixing blades, and introducing additional material into the chamber from the end ofsuch chamber in the void at the rear face of one of such blades.

24. The method of introducing. material into a rubber mixer having a mixing chamber and a rotary blade therein,.which comprises feeding the material into the space behind the rotating blade.

25. The method of introducing material into a mixer having a mixing chamber and rotating blades therein for working the material'back and forth in said chamber, which comprises feeding the material through one of the end walls of the mixing chamber into the vacant space at the rear facefof one of the blades.

26. The method of mixing 'powdered fill-` ing material or pigment with rubber which is being worked in a rubber mixer consisting of a mixing chamber with a rotor therein for working the mass back and forth in such chamber, which comprises introducing the powder through the head of the mixing chamber while the rubber mass is being vworked by the rotor.

27. The method of incorporating powder with rubber or like chunks, which are being worked back and forth in a suitable mixing chamber, by rotating blades which comprises introducing thepowderinto one end of the mixing chamber and into the space behind one of the blades while the blades are acting on the mass.'

28. The method of incorporating powder `with rubber chunks or the like, which are being mixed by a rotating blade in a suitable mixing chamber, which comprises feeding the powder by gravity into the space behind the blade..

29. The method of incorporating powder with rubber chunks or the like, which are being mixed by a rotating blade in a suitable mixing chamber, which comprises feeding the powder by gravity into the space behind the blade through'v the end wall of the chamber.

30. The method of mixing rubber and the like in a suitable mixing chamber by means of rotating blades which work the material back and forth in said chamber, which comy prises feeding material by gravity into the mixing chamber through the end of the latter at a point in the path of rotation ofone of said blades, so that such material can be drawn into the space at the rear of the rotating blade.

In witness whereof, we have hereunto setv 20 our hands on the 8th day o f January, 1919.

DAVID R. BOWEN'. CARL r. SCHNUCK. 

